Today, I was reviewing a book on childhood obesity for work, and I came across an interesting passage on the “thrifty gene.” It sounded familiar, probably something I learned about back in high school biology, but for some reason, the idea was new for me. Geneticist James Neel proposed the hypothesis in 1962 in his attempts to understand how diabetes survived natural selection.
I agreed. How did Type 1 diabetes, an autoimmune disorder with obvious negative and previously fatal effects, often inflicting children pre-reproductive stage, survive? Neel proposed it was once a survival advantage to be able to fatten quickly and survive seasons of food scarcity. We’re talking hunter-gatherer societies. And because it was such a survival advantage, it continues to be passed down generation after generation.
The only difference is now we don’t have to worry about famines. We keep eating and eating, but our bodies never have to endure hunger and depend on the survival mechanism of diabetes to eat away at our stored fat without our blood sugar dropping and keep us alive. No, our blood sugar keeps rising and rising until our bodies drop dead or malfunction.
But as little as this hypothesis may mean for the future of diabetes, it actually comforts me. It’s nice to think my disease once had a purpose, that evolution wouldn’t have weeded me out like I always thought it would if it weren’t for modern medicine. And even though I enjoy the casual post-apocalyptic story, I always envied the characters that survived because without daily injections of insulin and blood sugar readings, I thought I would surely die. But maybe I wouldn’t? Maybe I would be one of the few that survived?
We don’t live in a post-apocalyptic world. We don’t live in hunter-gatherer societies. We live amidst a diabetes epidemic. And why? So that when the next famine comes along, we have a chance at survival.
Sometimes, you need that silver lining, however silly it seems.